Arun,
This additional example is still irrelevant.
The difference occurs when the two values are passed as the "..." argument to
min(), which is a list and is what Magnus was using, versus your examples,
where the two values are passed as a single vector, which is coerced to
character:
> str(c(NA, "bla"))
chr [1:2] NA "bla"
as compared to:
> str(list(NA, "bla"))
List of 2
$ : logi NA
$ : chr "bla"
Unless there is something in the internal C code, since min() is a .Primitive,
where the lexical ordering of the two values NA and "bla" are relevant to the
processing of the values and the returned value (eg. a collating sequence issue
or a hierarchy of coercion issue), this appears to be a possible bug.
NOTE:
# Returns a int
> str(min(NA, "bla"))
int NA
# Returns a character
> str(min("bla", NA))
chr "bla"
However:
# Both return characters
> str(min(as.character(NA), "bla"))
chr "bla"
> str(min("bla", as.character(NA)))
chr "bla"
It would appear that in Magnus' example, that NA is passed as a logical in the
argument list may be relevant here.
BTW, I can reproduce Magnus' example on 3.0.2 on OSX (10.8.5).
Regards,
Marc Schwartz
On Sep 26, 2013, at 10:40 AM, arun <smartpink...@yahoo.com> wrote:
> min(c(NA,"bla"),na.rm=FALSE)
> [1] NA
>> min(c("bla",NA),na.rm=FALSE)
> [1] NA
> A.K.
>
>
>
> ----- Original Message -----
> From: Ista Zahn <istaz...@gmail.com>
> To: arun <smartpink...@yahoo.com>
> Cc: Magnus Thor Torfason <zulutime....@gmail.com>; R help
> <r-help@r-project.org>
> Sent: Thursday, September 26, 2013 11:36 AM
> Subject: Re: [R] min(NA,"bla") != min("bla", NA)
>
> Hi A.K.,
>
> On Thu, Sep 26, 2013 at 11:22 AM, arun <smartpink...@yahoo.com> wrote:
>> Hi,
>> min(5,1)
>> #[1] 1
>>
>>
>> min(c(1,5))
>> #[1] 1
>> min(c(1,5))==min(c(5,1))
>> #[1] TRUE
>>
>>
>>
>> min(c(NA,"bla"))
>> #[1] NA
>> min(c("bla",NA))
>> #[1] NA
>> min(c("bla",NA),na.rm=FALSE)
>> #[1] NA
>> min(c("bla",NA),na.rm=TRUE)
>> #[1] "bla"
>
> What is the point of this example? The OP's point was (I hope I am not
> putting words in his mouth) that the documentation for ?min says
>
> " If ‘na.rm’ is ‘FALSE’ an ‘NA’ value in any of the arguments will
> cause a value of ‘NA’ to be returned, otherwise ‘NA’ values are
> ignored."
>
> but that appears not to be true:
>
> min("bla", NA)
> [1] "bla"
>
> It's not clear to me how your example is relevant.
>
> Best,
> Ista
>
>>
>> A.K.
>>
>>
>>
>> ----- Original Message -----
>> From: Magnus Thor Torfason <zulutime....@gmail.com>
>> To: "r-help@r-project.org" <r-help@r-project.org>
>> Cc:
>> Sent: Thursday, September 26, 2013 11:07 AM
>> Subject: [R] min(NA,"bla") != min("bla", NA)
>>
>> Just ran these two statements:
>>
>>> min(NA,"bla")
>> [1] NA
>>
>>> min("bla", NA)
>> [1] "bla"
>>
>> And then reran with explicit na.rm=FALSE
>>
>>> min(NA,"bla", na.rm=FALSE)
>> [1] NA
>>
>>> min("bla", NA, na.rm=FALSE)
>> [1] "bla"
>>
>>
>> That seems wrong. Would this be considered a bug or is there a way to
>> explain these results in a different way?
>>
>> Best,
>> Magnus
>>
>> ps. Tested on R 3.0.1, 32 bit for Windows (as well as some older versions)
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